A319 flight crew reported encountering wake turbulence in trail of a B737 on the WATSN2 arrival to o...

Attributes
ACN	1292014
Time
Date	201509
Local Time Of Day	0601-1200
Place
Locale Reference	C90.TRACON
State Reference	IL
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR WATSN2
Flight Plan	IFR
Aircraft 2
Make Model Name	B737 Undifferentiated or Other Model
Flight Phase	Descent
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Experience	Flight Crew Last 90 Days 218
Events
Anomaly	Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Track / Heading All Types Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Wake Vortex Encounter

Narrative:

During descent on the WATSN2 RNAV arrival into ord and cleared to descend to and maintain 12;000 feet at hulls; at about 14;000 feet on the autopilot we encountered wake turbulence from the aircraft ahead of us. We rolled left and right in excess of 30 degrees before flying out of it. We enquired about the type of aircraft in front of us--it was a B-737. Shortly thereafter we re-entered its wake with the same result and immediately requested a slight deviation 10 degrees to the right. The approach controller stated he was unable to approve that due to departure traffic from O'hare. To avoid entering the wake a third time; I disconnected the autopilot and hand flew the aircraft slightly above and to the right of the RNAV path. This resulted in the failure to be level at hulls at 12;000 feet; crossing it instead about 500 feet high. Once level I re-engaged the autopilot and resumed the WATSN2 arrival. No further wake encounters occurred.

Original NASA ASRS Text

Title: A319 flight crew reported encountering wake turbulence in trail of a B737 on the WATSN2 arrival to ORD that resulted in rolls left and right in excess of 30 degrees.

Narrative: During descent on the WATSN2 RNAV Arrival into ORD and cleared to descend to and maintain 12;000 feet at HULLS; at about 14;000 feet on the autopilot we encountered wake turbulence from the aircraft ahead of us. We rolled left and right in excess of 30 degrees before flying out of it. We enquired about the type of aircraft in front of us--it was a B-737. Shortly thereafter we re-entered its wake with the same result and immediately requested a slight deviation 10 degrees to the right. The Approach Controller stated he was unable to approve that due to departure traffic from O'Hare. To avoid entering the wake a third time; I disconnected the autopilot and hand flew the aircraft slightly above and to the right of the RNAV path. This resulted in the failure to be level at HULLS at 12;000 feet; crossing it instead about 500 feet high. Once level I re-engaged the autopilot and resumed the WATSN2 Arrival. No further wake encounters occurred.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A319 flight crew reported encountering wake turbulence in trail of a B737 on the WATSN2 arrival to ord that resulted in rolls left and right in excess of 30 degrees.